'78 Merc T1: Upper Unit shaft oil seal -- Removal?

[Joe Sea Ray]

Am reposting w/ hopefully better wording. '78 Type 1. My oil seal -- for the vertical shaft -- came apart. I was told that replacement is easy, from the bottom of Upper Unit. Mine has a STAINLESS ring where the new seal should go. Is that just the remnants of the old seal? The new seal is black, rubberized, spring band, etc. Just wanted to be sure it's not a retainer that goes back on, etc. Also, best way to remove?? A tiny hub puller?? (Replacement from top of Upper would of course require removal of the main gearset, etc -- a real pain!) Seloc manual not helpful here. Thanks!!!!